Natural selection is the process by which organisms better adapted to their environment are more likely to survive and reproduce, passing on their advantageous traits to their offspring.

Adaptation refers to the inherited characteristics that help an organism survive and reproduce in its environment, resulting from natural selection.

The three main mechanisms of genetic variation are mutation, genetic recombination, and gene flow. Mutation introduces new alleles into a population, genetic recombination shuffles existing alleles, and gene flow transfers alleles between populations.

Evolution refers to the change in the genetic composition of a population over time, resulting from natural selection, genetic drift, and other evolutionary forces.

Speciation is the process by which new species are formed, typically involving the reproductive isolation of a population from its ancestral species.

Coevolution is the process by which two or more species evolve in response to each other's presence, often involving reciprocal adaptations and dependencies.

Symbiosis is the process by which two or more species live in close association, often benefiting from each other, including mutualism, commensalism, and parasitism.

Mutualism is the process by which two or more species benefit from each other's presence, often involving reciprocal adaptations and dependencies.

Commensalism is the process by which one species benefits from the presence of another species without harming it, often involving one species using the resources of another without causing harm.

Parasitism is the process by which one species benefits from the presence of another species at the expense of the other species, often involving one species exploiting the resources of another to its own advantage.

Competition is the process by which two or more species compete for the same resources, such as food, water, or territory, often resulting in negative consequences for one or both species.

Extinction is the process by which a population of organisms becomes extinct, typically due to environmental changes, competition, or other factors.

Convergent evolution is the process by which two or more species evolve similar traits in response to similar environmental pressures, often resulting in analogous structures or behaviors.

Divergent evolution is the process by which two or more species evolve different traits in response to different environmental pressures, often resulting in homologous structures or behaviors.

Parallel evolution is the process by which two or more species evolve similar traits independently of each other, often resulting in analogous structures or behaviors.